Virulence Diversity and Cas gene Cluster Analysis in Xanthomonas oryzae pv. oryzae Population of India

Author: Namburi Karunakar Reddy, M.K. Prasanna Kumar and Swathi S. Patil

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Abstract

Exopolysaccharide (EPS) and Xanthomonadin pigment quantification in 39 Xanthomonas oryzae pv. oryzae (Xoo) isolates are investigated in this work, as well as any implications for pathogenicity. With levels ranging from 29 mg to 92 mg, EPS generation, which is essential for the development of the disease and host colonisation, differed among isolates. Longer lesion lengths were connected with certain high EPS producers but not with others, demonstrating the multiple impacts on pathogenicity. When Xanthomonadin pigments were quantified, different levels were found for different isolates, although their combined influence on lesion duration varied. Variations in the presence of Cas genes were discovered through the analysis of CRISPR-Cas gene clusters, with some isolates, KPXoo5, KPXoo15, KPXoo26 and KPXoo32 having the entire set and others lacking specific cas genes. These results highlight the genetic variation of Xoo strains and highlight the need for more research on the functional effects of Cas gene variants. Overall, this study advances our knowledge of Xoo pathogenicity and may have implications for gene-editing studies and crop protection.

Keywords

Xanthomonas oryzae pv. oryzae, Exopolysaccharide, CRISPR-Cas

Conclusion

The production of exopolysaccharide (EPS) and quantification of Xanthomonadin pigments were assessed to understand their roles in pathogenicity. The results showed that EPS production levels varied among isolates, potentially influencing lesion development. Xoo isolates with higher EPS production tended to have longer lesions, suggesting a correlation between EPS production and virulence. Regarding the CRISPR-Cas immune system, it was shown that certain Xoo isolates had a comprehensive complement of cas genes, indicating the presence of an operational and effective defence mechanism against exogenous genetic elements. Nevertheless, it is noteworthy that two isolates exhibited the absence of the Cas4 gene, a crucial component in spacer acquisition and adaptation. This genetic variation may affect their capacity to counteract novel challenges effectively.

References

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How to cite this article

Namburi Karunakar Reddy, M.K. Prasanna Kumar and Swathi S. Patil (2023). Virulence Diversity and Cas gene Cluster Analysis in Xanthomonas oryzae pv. oryzae Population of India. Biological Forum – An International Journal, 15(9): 523-527.